﻿410 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1927 
  

  

  the 
  stimulus 
  of 
  spontaneous 
  action 
  proceeds. 
  The 
  experiments 
  made 
  

   lator 
  by 
  K()|)iV' 
  on 
  the 
  gypsy 
  moth 
  are 
  more 
  definite 
  in 
  this 
  respect. 
  

   Koj)oc 
  I'ounil 
  that 
  if 
  a 
  nerve 
  center 
  is 
  removed 
  from 
  a 
  caterpillar, 
  or 
  

   a 
  pair 
  of 
  j;an«jjlionic 
  connective 
  cords 
  is 
  cut, 
  no 
  regeneration 
  of 
  the 
  

   tissues 
  (nkos 
  place 
  and 
  that 
  the 
  injured 
  larva 
  will 
  transform 
  into 
  a 
  

   nu)(h 
  having 
  the 
  same 
  physical 
  defect. 
  Operations 
  are 
  more 
  easily 
  

   performed 
  on 
  the 
  caterpillar, 
  and 
  the 
  brain 
  may 
  be 
  excised 
  or 
  its 
  

   connectives 
  severed 
  without 
  injury 
  to 
  the 
  subcBsophageal 
  ganglion. 
  

   Moths 
  that 
  have 
  been 
  reared 
  from 
  caterpillars 
  in 
  which 
  the 
  brain 
  

   has 
  been 
  made 
  functionless 
  through 
  the 
  cutting 
  of 
  its 
  connectives, 
  

   Kopec 
  says, 
  can 
  both 
  walk 
  and 
  lly 
  and 
  perform 
  other 
  normal 
  move- 
  

   ments, 
  but 
  they 
  have 
  no 
  incentive 
  to 
  do 
  so, 
  and 
  males 
  will 
  sit 
  all 
  

   day 
  in 
  cages 
  with 
  normal 
  females 
  without 
  showing 
  any 
  reaction 
  to 
  

   their 
  presence, 
  a 
  behavior 
  quite 
  ditTeront 
  from 
  tliat 
  of 
  males 
  with 
  a 
  

   functiiuial 
  brain. 
  A 
  female 
  moth 
  deprived 
  of 
  her 
  brain 
  also 
  shows 
  no 
  

  

  wVvC.t^^ 
  5kGl 
  \TMC 
  

  

  Kuj, 
  C. 
  — 
  A 
  oatorpiHivr 
  with 
  tlio 
  lx>dy 
  waU 
  nnuoved 
  from 
  the 
  left 
  side, 
  showing 
  the 
  

   principal 
  luter«!il 
  ors::uis 
  u'xoept 
  the 
  tracheal 
  system) 
  and 
  the 
  position 
  of 
  the 
  

   wutral 
  nervous 
  system 
  (Ur, 
  SirGng. 
  VXC) 
  

  

  Ah, 
  anns; 
  Br, 
  brain; 
  (>. 
  cmp 
  : 
  Ht, 
  heart: 
  Int. 
  intestine; 
  Mai, 
  Malpighian 
  tubule 
  

   Uhrrx" 
  on 
  twoh 
  side, 
  but 
  only 
  one 
  shown 
  full 
  length 
  > 
  ; 
  Phy, 
  pharynx; 
  Rcct, 
  rectum; 
  

   SAtJJ. 
  silk 
  .slnnd 
  ; 
  ^^rtrnJ;. 
  snlvvsophagoal 
  ganglion; 
  Vent, 
  veutriculus, 
  or 
  stomacli 
  ; 
  

   rvt\ 
  v\nitral 
  nerve 
  \.vrd 
  

  

  reaction 
  lo 
  the 
  nuuing 
  instinct, 
  though 
  she 
  can 
  be 
  mated 
  with 
  a 
  

   normal 
  male. 
  Mated 
  brainless 
  females 
  often 
  lay 
  their 
  eggs, 
  but 
  they 
  

   do 
  so 
  in 
  an 
  irregular, 
  abnormal 
  manner. 
  From 
  these 
  facts 
  Kopec 
  

   draws 
  the 
  conclusion 
  that 
  the 
  insect 
  brain 
  is 
  the 
  nerve 
  center 
  from 
  

   which 
  piMceeds 
  the 
  stimulus 
  that 
  activates 
  the 
  mating 
  instinct, 
  and 
  

   that 
  the 
  brain 
  is 
  also 
  the 
  coordinating 
  center 
  for 
  the 
  process 
  of 
  

   egg 
  laying. 
  l\v 
  other 
  similar 
  experiments 
  Kopec 
  obtained 
  evidence 
  

   that 
  the 
  suKvsv^phageal 
  gimglion 
  of 
  the 
  gypsy 
  moth 
  is 
  a 
  reflex- 
  

   inhibiting 
  center, 
  since, 
  after 
  its 
  removal, 
  the 
  insects 
  become 
  highly 
  

   excitable 
  to 
  stimuli 
  and 
  their 
  reflex 
  movements 
  are 
  especially 
  strong. 
  

   The 
  moths 
  in 
  Mii^ 
  McCracla}n*s 
  experiments, 
  therefore, 
  were 
  inca- 
  

   pable 
  of 
  spontaneous 
  action 
  but 
  were 
  susceptible 
  to 
  artificial 
  stimu- 
  

   lation 
  Invause, 
  by 
  the 
  removal 
  of 
  the 
  entire 
  head, 
  they 
  had 
  lost 
  both 
  

   the 
  initiative 
  and 
  the 
  inhibitory 
  centers. 
  

  

  Ihirsuing 
  her 
  exjx^rimeiiis. 
  Miss 
  MeCracken 
  found 
  that 
  the 
  entire 
  

   thorax 
  of 
  the 
  silkworm 
  moth 
  could 
  be 
  removed 
  without 
  interference 
  

  

  